今日更新：Composite Structures 7 篇，Composites Part A: Applied Science and Manufacturing 2 篇，Composites Part B: Engineering 3 篇，Composites Science and Technology 1 篇
Composite Structures
Advances in composite phase change materials based on high performance three-dimensional (3D) skeletons: Properties, strategies and applications
Qian Runda, Liu Meng, Lu Xitao, Qing Chunyao, Zou Deqiu
doi:10.1016/j.compstruct.2023.117711
基于高性能三维（3D）骨架的复合相变材料的进展：性能、策略和应用
Phase change materials (PCM) have received widespread attention due to their outstanding advantages, such as high latent heat, little temperature fluctuation, and good chemical and physical stability. However, the low thermal conductivity and leakage of PCM significantly limit their applications. The efficient strategy of using high thermal conductivity materials to construct three-dimensional (3D) skeletons for encapsulating PCM is widely considered to simultaneously improve thermal conductivity and structure stability. Herein, this paper reviews the recent research progress on enhancing the thermal performance and structure stability of PCM through the construction of 3D skeletons using various methods, including low-dimensional material assembly, foam templates, and 3D printing strategies. The construction strategies of 3D skeleton from the micro (low-dimensional material assembly) to the macro (foam templates and 3D printing) are highlighted and compared. Furthermore, diverse applications are summarized and analyzed. Finally, challenges, opportunities and solutions are put forward.
Analysis of the Transfer, Flexural Bond and Anchorage Lengths of Pretensioned FRP Reinforcement Based on Eurocode
Jokūbaitis Aidas, Valivonis Juozas
doi:10.1016/j.compstruct.2023.117712
基于欧洲规范的预拉伸玻璃钢加固的传递、挠曲粘结和锚固长度分析
Current design codes in North America have guidelines for assessing the anchorage zone of pretensioned fiber reinforced polymer (FRP) reinforcement. However, there is no comparison of the Eurocode approach with experimental data or suggestions for its application for prestressed FRP reinforcement. Therefore, the main objective of this article is to provide a comparison of available data in the literature on the transfer, flexural bond, and anchorage length of different types of FRP reinforcement with Eurocode and to provide insight on the adaptation of this code. The database of more than 300 and 100 specimens with the results of the transfer and flexural bond lengths is used, respectively. This database is used to derive and propose the parameters that describe the type and surface of pretensioned FRP reinforcement based on the Eurocode approach. Furthermore, the influence of shear reinforcement and the type of pretensioned reinforcement release (gradual and sudden) is taken into account. The Eurocode approach with the coefficients proposed for different FRP reinforcements on average gave the best prediction of the experimental transfer, flexural bond, and anchorage length results compared to the North American design codes for FRP reinforcement and the Eurocode for steel strands.
An efficient multi-objective optimization framework for thin-walled tubular deployable composite boom
Bai Jiang-Bo, You Fei-Yan, Wang Zhen-Zhou, Fantuzzi Nicholas, Liu Qing, Xi Hao-Tian, Bu Guang-Yu, Wang Yong-Bin, Wu Shi-Qing, Feng Rui, Liu Tian-Wei
doi:10.1016/j.compstruct.2023.117713
薄壁管式可展开复合吊杆的高效多目标优化框架
As a crucial structural component in space applications such as solar sails and solar arrays, the thin-walled tubular deployable composite booms (DCBs) demonstrate extensive utilization by employing stored elastic strain energy to achieve folding and deploying functions. This paper introduces a multi-objective optimization framework that integrates an analytical model with a genetic algorithm. By utilizing a multi-objective evolutionary algorithm based on de-composition (MOEA/D), the optimization objectives of minimizing folding moment and maximizing bending stiffness are pursued. Multiple constraints associated with failure avoidance, laminate stacking sequence design principles, and the folding moment range of actuator in the folding mechanism are considered in the optimization. The multi-objective optimization design of the tubular DCBs is performed to obtain the optimal combinations of cross-sectional radius, central angle, and ply scheme. Experimental validation confirms the efficacy of the optimization results. Additionally, an in-depth analysis on the influence of genetic algorithm types, hyperparameters, and different design variables on the optimization outcomes is thoroughly discussed. The findings of this study offer significantly insights for the practical engineering applications of tubular DCBs.
Ultrasonic lamination defects detection of carbon fiber composite plates based on multilevel LSTM
Zhang Fengyi, Wang Lihua, Ye Wenjing, Li Yan, Yang Fan
doi:10.1016/j.compstruct.2023.117714
基于多层次 LSTM 的碳纤维复合板超声波层压缺陷检测
During the production of carbon fiber composites (CFC), various forming methods and complex processes can introduce different types of defects, with lamination defects being a major concern. In this paper, we propose a multilevel Long Short-Term Memory (LSTM) neural network combined with ultrasonic detection to identify the lamination defects in carbon fiber composites. Unlike conventional ultrasonic detection that requires multiple sets of probes, this method only employs a one-to-one transmission and reception mode. The COMSOL-Multiphysics finite element software is utilized to simulate the ultrasonic transmission and generate the necessary ultrasonic data. By incorporating multiple levels of learning, the accuracy and convergence of the traditional LSTM can be obviously enhanced. This approach uses ultrasound waveform data collected from a single set of probes to predict the locations and sizes of lamination defects. Based on fewer than 10000 datasets where each dataset represents a waveform, the numerical results demonstrate a prediction accuracy of over 90% for defect position and size. Moreover, the multilevel LSTM method exhibits convergence, and incorporating more data can further promote the prediction accuracy. This method offers a time-saving, labor-saving, and cost-effective solution for detecting and analyzing defects in CFC.
Fused deposition modeling to predict inter-layer weld strength of polyvinylidene fluoride and its MWCNTs-reinforced composites
Zhang Huiying, Xiao Jie, Chen Ye, Wang Huaping
doi:10.1016/j.compstruct.2023.117715
通过熔融沉积建模预测聚偏氟乙烯及其 MWCNT 增强复合材料的层间焊接强度
Fused deposition modeling (FDM) printed parts have poor mechanical properties in comparison to injection molding parts, which is attributed to the insufficient welding of extrusion filaments at the inter-layer adhesion interface. This paper proposes a methodology for predicting and analyzing the weld strength of FDM printed parts using poly(vinylidene fluoride) (PVDF) as the raw material. A temperature field simulation and weld strength prediction are established and used to predict inter-layer weld strength. The relative error between predicted weld strength and the experimental value of FDM printed PVDF under different parameters is small, indicating that the method has good accuracy. Moreover, it can be extended to PVDF composites with different MWCNTs content, exhibiting good versatility. This method provides valuable theoretical guidance for the research of polymer composites in FDM process and offers opportunities for the application of FDM in specific fields.
Crashworthiness study of tubular lattice structures based on triply periodic minimal surfaces under quasi-static axial crushing
Wan Mincen, Hu Dayong, Zhang Hongbo, Pi Benlou, Ye Xubin
doi:10.1016/j.compstruct.2023.117703
准静态轴向挤压下基于三重周期性极小曲面的管状晶格结构的耐撞性研究
This study explored the crashworthiness performance of four types of tubular lattice structures based on triply periodic minimal surfaces (named TPMS-T)—Diamond, Gyroid, IWP, and Primitive. Their axial crushing behaviors were examined by experiments and numerical simulation, and compared against typical tubes. TPMS-T outperformed traditional tubes in terms of crashworthiness. Subsequently, the effects of the relative density (ρ), density gradient and hybrid design on the crushing behaviors of TPMS-T were analyzed numerically. Results showed that ρ had a significant effect on crashworthiness performance and deformation modes, and density gradient and hybrid design could lead to lower initial peak crushing force (Fp), higher specific energy absorption (SEA), and larger crushing force efficiency (CFE). Finally, numerical investigations of the improved TPMS-T structures were shown to enhance crashworthiness performance through interaction with tube walls.
Towards Composite Suspension Control Arm: Conceptual Design, Structural Analysis, Laminate Optimization, Manufacturing, and Experimental Testing
Komurcu E., Kefal A., Abdollahzadeh M.A., Basoglu M.F., Kisa E., Yildiz M.
doi:10.1016/j.compstruct.2023.117704
迈向复合悬架控制臂：概念设计、结构分析、层压优化、制造和实验测试
The automotive industry needs composite materials to decrease the weight of new-generation vehicles whilst increasing their strength. In this study, one of the critical (load bearing) components of automobiles, i.e., the suspension control arm made of steel, is fully redesigned for its suitable manufacturing using composite materials. To this end, innovative mechanical simulation methods are developed and coupled to perform the design, analysis, and optimization of the automotive suspension control arm. The main design/optimization criteria are set to reduce no less than 75% weight of the metal control arm and increase its safety by at least 60% by using composite materials and a new geometry suitable for mass production. To predict the deformation-stress state of the control arm, a four-node quadrilateral shell element is implemented based on the kinematics of refined zigzag theory (RZT). Once verified numerically, the computer implementation of the RZT is combined with the optimization algorithm to achieve the optimum laminate stacking sequence of the control arm. Accordingly, prototypes of the composite control arms with optimum lamination plans are manufactured and then experimentally tested under the loading and constraint conditions defined at the conceptual design stage. The numerical and full-scale experimental results are compared, and the RZT models are comprehensively validated. Hence, the advantages of the overarching design-analysis-optimization strategy presented herein are revealed for redesigning and manufacturing automobile parts from composite materials.
Composites Part A: Applied Science and Manufacturing
Facile fabrication Ni@SiO2/C derived from polysilsesquioxane as strong and broadband microwave absorbers with infrared stealth, flame retardant, and water resistant functions
Du Hanying, Ren Jiaqi, Zhang Donglin, Li Xiang, Zhang Wenchao, Yang Rongjie
It remains a great challenge for magnetic/carbon-based microwave absorbers to achieve both strong and broadband absorption, especially at ultra-low filling ratio. Herein, nickel nanoparticles supported on porous silica/carbon composite (Ni@SiO2/C) derived from POSS was prepared by a facile method. The carbonized Ni@SiO2/C composite offers the following advantages: i) the three-dimensionally porous POSS-derived SiO2/C skeleton provides electron transport paths and enhances conductive dissipation; ii) the porous magnetic/carbon composite provides interfacial polarization to enhance dielectric loss and forms strong magnetic coupling network to enhance magnetic loss; iii) multiple reflections and scattering between the porous framework enhance electromagnetic waves attenuation. Notably, the optimized Ni15@SiO2/C750 achieves high reflection loss of −58.5 dB, and broad effect absorption bandwidth of 8 GHz with a thickness of 2 mm at an ultra-low filling ratio of 3 wt%. Besides, the Ni15@SiO2/C750 has multiple properties of infrared stealth, flame retardancy, and water resistance.
How to regulate moisture-induced stresses in composites: The answer from nanostructure of S2 layer in Wood cell wall
Chen Mingyang, Zhang Chi, Ke Liao-Liang
doi:10.1016/j.compositesa.2023.107889
如何调节复合材料中由湿气引起的应力：木材细胞壁 S2 层纳米结构的答案
S2 layer of the Wood cell wall is fundamentally a biocomposite with strong hygroscopicity and undergoes significant changes in mechanical properties upon water adsorption. How the internal stress develops during the adsorption process is still unclear. By employing a multi-scale modeling scheme, we successfully resolve the stress distributions within the S2 layer at different moisture levels. We find that the shear stress developed on the fibril-matrix interface is much smaller than that of ordinary fiber-reinforced composites with the same geometrical dimensions due to the heterogeneous nature of the microfibrils. Besides, we demonstrate that the stress developed during dehydration is larger than that during hydration, which is attributed to the fact that the amorphous polymers comprising the matrix suffer from softening upon water adsorption. These unraveled mechanisms can deepen people’s understanding on the origin of the moisture-induced stress in the S2 layer.
Inner superhydrophobic materials based on waste fly ash: Microstructural morphology of microetching effects
Pang Bo, Zheng Heping, Jin Zuquan, Hou Dongshuai, Zhang Yunsheng, Song Xiaoyun, Sun Yanan, Liu Zhiyong, She Wei, Yang Lin, Li Mengyuan
doi:10.1016/j.compositesb.2023.111089
基于废弃粉煤灰的内超疏水性材料：微蚀效应的微观结构形态
Superhydrophobic technology in construction can effectively improve the barrier ability of the substrate to harmful water-based erosion media, among which the coating scheme is the most practical choice at present, but it may easily fail due to mechanical damage. Therefore, the current research focus has shifted to the development of internal superhydrophobic materials (ISMs) that maintain stable hydrophobicity even under harsh conditions of use and do not rely on expensive fluor-based surface modifications. In this study, the topological structure of waste denitrification fly ash (FA) was constructed using an innovative method, by precisely controlling the etching medium concentration and the form of FA, a one-step process was developed to create ISM with excellent matrix strength and strong waterproof properties. In this study, the alkaline environment generated by FA hydration was used to induce the silica-hydrogen bond dehydrogenation of polymethylhydrosiloxane (PMHS) and the free ammonium ion deamination to toughen the film; PMHS and liquid phase are used to produce the oil-water phase, and the oil film adheres to the surface of the generated NASH and sodium silicate crystals; The porous inner surface of ISM is formed with hydrogen- and ammonia-induced rough structure; The synthesized ISM retains superhydrophobicity and less compressive strength reduction value, and its superhydrophobicity even at damaged or friction interfaces. The material preparation method provides a good foundation and innovative design concept for the seepage prevention and maintenance of concrete structures, the construction of aerated FA bricks, the preparation of foam insulation materials, and the batch utilization of waste FA.
建筑中的超疏水技术可以有效提高基材对有害水基侵蚀介质的阻隔能力，其中涂层方案是目前最实用的选择，但它很容易因机械损伤而失效。因此，目前的研究重点已转向开发即使在苛刻的使用条件下也能保持稳定疏水性的内部超疏水性材料（ISM），而不依赖于昂贵的氟基表面改性。本研究采用创新方法构建了废弃脱硝粉煤灰（FA）的拓扑结构，通过精确控制蚀刻介质的浓度和 FA 的形态，开发出一种一步法工艺，从而制造出具有优异基体强度和强大防水性能的 ISM。在这项研究中，利用 FA 水合产生的碱性环境诱导聚甲基氢硅氧烷（PMHS）的硅氢键脱氢和游离铵离子脱氨以增韧薄膜；利用 PMHS 和液相产生油水相，油膜附着在生成的 NASH 和硅酸钠晶体表面；ISM的多孔内表面形成氢气和氨气诱导的粗糙结构；合成的ISM保持超疏水性，抗压强度降低值较小，即使在损坏或摩擦界面也能保持超疏水性。该材料制备方法为混凝土结构的防渗和养护、加气 FA 砖的建造、泡沫保温材料的制备以及废弃 FA 的批量利用提供了良好的基础和创新的设计理念。
Evolution of stiffness in flax yarn within flax fiber reinforced composites during moisture absorption
Wang Jingjing, Li Yan, Li Qian, Long Yu, Yu Tao, Li Zhuo
doi:10.1016/j.compositesb.2023.111096
吸湿过程中亚麻纤维增强复合材料中亚麻纱线刚度的变化
This study aims to investigate the evolution of stiffness in flax yarn within flax fiber reinforced composites (FFRCs) during moisture absorption, focusing on the influence of moisture content on the microstructure of flax fibers. To characterize the hygroscopic mechanical behaviors of flax yarns in FFRCs, the hygroscopicity and tensile properties of dried and impregnated flax yarns were tested at various humidity levels. A multi-scale modeling approach was utilized to simulate the stiffness in flax yarn within FFRCs, encompassing the modeling of cell wall layers of the flax elementary fiber, flax elementary fiber and twisted flax yarn. Specifically, the variation trends of the microfiber angle (MFA) in the S2 layer and the stiffness degradation of the combined amorphous matrix (CAM) with respect to relative moisture content (RMC) were proposed and determined through simulation and inversion calculation. The study reveals that the MFA in the S2-layer is the most crucial parameter affecting the longitudinal elastic properties of flax yarn in FFRCs, while the stiffness degradation of the CAM significantly influences the transverse elastic properties. Finally, this study establishes a relationship between the overall stiffness of flax yarn in FFRCs and the RMC. This relationship provides a parameter foundation for accurately predicting the mechanical properties of FFRCs during moisture absorption.
A comparative study on the oxidation behavior and failure mechanisms of conventional NiCoCrAl alloy and in-situ composite AlCoCrFeNi2.1 eutectic high-entropy alloy at 1300 °C
Lu Jie, Zhang Han, Ren Guoliang, Chen Ying, Luo Lirong, Cai Huangyue, Shan Xiao, Zhang Xiancheng, Zhao Xiaofeng
doi:10.1016/j.compositesb.2023.111097
传统镍钴铬铝合金与原位复合 AlCoCrFeNi2.1 共晶高熵合金在 1300 °C 下的氧化行为和失效机理对比研究
We present a comparative study on oxidation behavior and failure mechanisms of conventional NiCoCrAl alloys doped with Y and Hf (CNA) and in-situ composite AlCoCrFeNi2.1 eutectic high-entropy alloy doped with Y and Hf (ISC-EHEA) at 1300 °C. We demonstrate that the ISC-EHEA has much stronger resistance to surface rumpling and oxide spallation than CNA. Hybrid molecular dynamics (MD) and Monte Carlo (MC) simulations show that the diffusion coefficients of the metal elements in the Al-depletion layer of the ISC-EHEA are 50 % lower than those in the CNA. The low diffusion coefficients lead to low growth stress in the thermally grown Al2O3 scale on the ISC-EHEA and improve the creep resistance of the metal in contact with the scale, thus preventing the occurrence of rumpling. The oxidation rate constant of the ISC-EHEA is ∼32 % lower in comparison to those of the CNA, which is attributed to the coarser columnar Al2O3 grains that effectively mitigate grain boundary diffusion. The rumpling-free metal/oxide interface, the low residual stress and the low oxide growth rate for the ISC-EHEA result in strong resistance to scale spallation. Owing to the strong scale/alloy bonding at the interface and the build-up of strain energy during prolonged oxidation, damage in the Al2O3 scale on the ISC-EHEA is initiated as surface cracks rather than interface decohesion. When re-oxidized at 1300 °C, the ingress of oxygen along the surface cracks results in fast growth of new oxides at the metal/oxide interface, which causes local stress concentration, interface crack propagation and scale spallation.
Mechanical, thermal insulation, and ablation behaviors of needle-punched fabric reinforced nanoporous phenolic composites: The role of anisotropic microstructure
Cai Hongxiang, Niu Bo, Qian Zhen, Li Tong, Wang Peng, Li Liang, Cao Yu, Zhang Yayun, Long Donghui
doi:10.1016/j.compscitech.2023.110325
针 刺织物增强纳米多孔酚醛复合材料的机械、隔热和烧蚀行为：各向异性微结构的作用
Needle-punched fabric reinforced nanoporous phenolic composite (NPC) is a kind of promising ablative thermal protection material for spaceflight. However, in practical applications, typically anisotropic microstructure of NPC may lead to different performances and damage mechanisms under various directional mechanical or thermal loads. Herein, NPC is prepared and cut into specimens along three typical plane directions including XY-plane (0°), Z-plane (90°), and transitional-plane (45°), and their mechanical, thermal insulation, and ablation behaviors are systematically investigated. Benefiting from the woven fabric in XY-plane, NPC in 0°-plane direction exhibits highest tensile strength (169.2 ± 12.6 MPa), and CT image-based simulation further verifies that woven fabrics are primary load-bearing structure. Meanwhile, NPC in 45°-plane direction shows highest compressive strength (443.1 ± 18.2 MPa) but low compressive stress at low strain, demonstrating a weak bonding between two layers of woven fabrics. Moreover, the heat transfer simulation indicates that horizontally stacked woven fabrics effectively protect the internal material from thermal erosion, thus NPC in 0°-plane direction exhibits optimal thermal insulation. The ablation testing and micro-CT observations further demonstrate that the angle between woven fabric and thermal load significantly influences the ablation mechanism. The present work will further promote the structural reliability and optimization of needle-punched composites.
